Discovery may lead to artificial skin that senses touch, temperature

Science have made a breakthrough that combines a resin with tiny gold particles to create a flexible sensor that could one day be integrated into electronic skin

A major roadblock for artificial limbs is that they simply do not feel like real limbs. Even with movement assisted by robotics, an artificial limb won’t ever let you touch and feel the texture of something, or feel the heat radiating from the sun or a hot stove. A team of scientists at the Technion -Israel Institute of Technology have made a discovery that may come to change that.

The scientists have created a flexible sensor which could one day be integrated into electronic skin (e-skin) and then attached to prosthetic limbs, to allow amputees to sense their environment once more. What makes the sensor unique is that it can simultaneously detect three types of data: touch, humidity and temperature, much like real skin does. The new sensor is supposedly also ten times more sensitive than conventional touch-based e-skin sensors.

While flexible sensors are nothing new, there are a few requirements that need to be fulfilled before they can be deployed to the consumer market, and until now, those requirements haven’t been met. They need to be able to function on a low voltage so that they can be used in portable devices with batteries; they need to be able to measure a range of different pressures and detect several types of environmental data at once.

The new sensor has all of the required qualities, thanks to it’s nano-technology based design. The device uses “monolayer-capped nano-particles”, roughly 5-8 nanometers in diameter. The particles are made of gold and connected by molecules called “ligands”. Professor Hossam Haick of the Institute, has a good analogy: “Monolayer-capped nanoparticles can be thought of as flowers, where the center of the flower is the gold or metal nanoparticle and the petals are the monolayer of organic ligands that generally protect it,”

And that’s why Data has a slight golden gleam in his skin

The team discovered the capabilities of the material when they layered the nano-particles on a substrate of PET plastic. They discovered that the nano-particles would conduct electricity differently depending on how the plastic was bent. In essence, bending brings some particles closer together, or farther away, thereby affecting how quickly electrons can make the leap from nano-particle to nano-particle.

The substrate fulfills an important function beyond simply holding the sensor; the thickness of the material used will affect how sensitive the sensor is. By using various types of substrates, the sensors have a wide range of applications, beyond the biomedical one. They could, for example, come to replace strain gauges and be used for measuring the strain on bridges or other structures.

Via Phys.org